Although this is not intended to be a tutorial, here are the basic schematics and construction details for the dress:

Bodice: Both back and front are made from two pieces: the outside piece is cut with the to-be-gathered edge alonfg the crosswise grain, while the inside piece with the to-be-gathered edge along the lengthwise grain. The two pieces attach at the line where the schematic points at attaching elastic. The elastic is sewn in the seam. At the end of the post there are some sequential photos of the process.

Skirt:

Other notes on construction:

The seam that attches the skirt to the bodice is reinforced with 1/8" elastic (sewn into the seam;

Breast pads (from a swimming suit) inserted in the bodice (between the two layers). The pads from the craft store were too rigid and left a rather visible outline;

The shoulder band is attached only to the seam that joins bodice with skirt.